110 developers rocked up to One Canada Square, Canary Wharf recently for the London-leg of the PayPal search to find the best hackers across ten of the world's coolest cities.

110 developers rocked up to One Canada Square, Canary Wharf recently for the London-leg of the PayPal search to find the best hackers across ten of the world's coolest cities.

The PayPal Battle Hack is a Hackathon series for the world's best and brightest developers. Teams come to test their skills, armed with their hacking smarts and awesome ideas for developing apps for social good. Following on from seven successful Hackathons in cities from Tel Aviv to Seattle, London teams went head-to-head, battling to win a place at the final in Silicon Valley this weekend and a chance to win a cool $100,000.

From kick-off at 1.30pm, we knew competition was going to be fierce, with hackers pausing only for food, beer and that all-time inconvenience - sleep, to turn their ideas into reality. Our five judges (from PayPal, Just Giving, Hailo, Anthemis and Tech Stars) had a tough time deciding which team would go through to the final as the quality of entries was so high, but stand-out teams did quickly emerge;

Neighbour.ly - A mobile web app that allows users to define a neighbourhood and lend household items and goods within the local community.

Bigger Issue - An app that allows you to buy a Big Issue (magazine handed out by homeless people in the UK) using text messages and PayPal

Kitty List - An app that established a shared kitty that is then used to give people an incentive to do community-based chores.

Twenty four hours after hacking began, our London hack heroes were beginning to emerge, with a killer app found in the form of Candle Path - an app that finds the safest way home at night. The app uses open data available through local authorities for street lights and plots the safest, best-lit route home. The app can also warn family or friends when users deviate from the safest path (available as a subscription). Candle Path is made-up of a team of four friends from the Nottingham University Hacking Society, Adam Gask, Simon Lotts, Joe Nash and Oluwatosin Afolabi. The team also won the "Best Idea" award at the event, wowing the judges with both their creative smarts and their hacking expertise and execution.

We'll see them again, along with nine other winning teams, for the final Battle Hack in Silicon Valley this weekend and the chance to win $100,000.